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abra
Sep21-04, 09:45 AM
Hi everyone. I'm new in the forum and I'd need an help to solve this equation (sorry, I think it's quite easy but I'm not an expert of mathematics..):

a*x + b*ln(x) = c

where a, b, c are parameters and I need to find the value of x.

Do I need to use techniques of differential equations?

Thanks a lot for any help.

TenaliRaman
Sep21-04, 10:24 AM
You need to use Numerical Techniques.
Have u come across Newton Raphson method ? It should do just fine on this one.

-- AI

abra
Sep21-04, 10:53 AM
No, I've never used the Newton Raphson method.. thanks, i'll have a look to this technique, however, I suppose I need to use some maths softwares to compute the result, isn't it?

Gokul43201
Sep21-04, 11:06 AM
No. Any scientific calculator will work. You could also use Excel, if you choose.

Hopefully, you won't have to go through too many iterations.

HallsofIvy
Sep21-04, 07:55 PM
There is also the "Lambert's W" function. It is defined specifically as "W(x) is the y satisfying yey= x". In other words, it is the inverse of the function xex.